My bf (27M) slept with a 17F on a trip he went on with two of his friends 28M + 19M and they invited 2 random girls they met online after posting an ad inviting randoms to this trip. There were 3 rooms in the airbnb - 1 with bunk beds (2 random girls ended up taking) and two double beds (27M+17F) + (28M + 19M). My bf claims it was too inconvenient to swap to the bunk bed room considering the two girls who were strangers had entered the room already and him despite being the only guy on this trip who had a girlfriend made it logical to sleep on the same bed as this minor because it meant ‘nothing would happen between them.’ He didn’t want to mention this to me till days after the trip, despite during planning telling me he would sleep on a bunk bed so he wouldn’t be sleeping with a girl. He claims the 17F calls him her best friend and they are close texting every day. I yelled at him telling him how unethical it was to sleep on the same bed as 17F especially since she is a minor (8m away from being 18) and told him to immediately remove her from all socials and let her know that as his gf I am not okay with them engaging in such a relationship with an inappropriate nature despite being certain nothing sexual is going on. I told my bf that it is majorly inappropriate that she feels safe enough to sleep with him in a bed when he has a girlfriend and choose to sleep with him out of all the people on this trip. AITA for making him block this girl as now he is trying to tell me it was unreasonable to drag this girl into our fight as well?